1. Field of the Invention
This invention relates to valves and particularly to a new and improved high force-gain valve which is inherently force balanced to permit quick and easy opening and closing thereof.
2. Description of the Prior Art
Many different types of valves are used to control the flow of fluids. Particular difficulties can arise, however, in valves which are employed to control fluid under high pressure. Force-gain can be defined as the ratio of the output force to the input force. Many typically-configured prior art valves have low force-gain in which a relatively powerful actuator is required to overcome the force of the high pressure fluid to which the valve component which varies the fluid flow is exposed. For example, in a typical poppet valve having a force-gain of only 1.5, the actuator would have to supply a 2,000 pound force in order to open a one square inch poppet against a 3,000 psi fluid. In addition to being expensive and bulky, such powerful actuators are heavy, a disadvantage where overall valve weight is an important factor, such as in aircraft or guided missile applications. Further, the necessity of such a powerful actuator eliminates from the choice of potential actuator types the typically smaller, lower powered and less expensive actuators, such as solenoids and cams.
Certain valve applications may also require quick opening, closing and precise positioning of the valve. For example, valves used as directional control thrusters in missile propulsion and control systems necessitate precisely timed, short bursts of high pressure fluid from the valves. The bulky, powerful actuators described earlier used in many prior art valves to control the flow of high pressure fluid, however, do not lend themselves to quick opening and closing as do the lower powered actuators, such as solenoids and small servoactuators. Thus, fast reaction can be difficult to achieve in a high pressure valve.
In view of the above mentioned problems, it is therefore an object of the present invention to provide a valve which is configured to control the flow of high pressure fluid using a relatively low powered actuator.
Another object of the present invention is to provide a valve for high pressure fluid which can be quickly opened and closed and precisely positioned to intermediate positions.
Yet another object of the present invention is to provide a valve for high pressure fluid which is lightweight and relatively inexpensive.